This invention relates generally to microphone holders, and in particular to a microphone holder that is adapted to be co-operable with a microphone housing and securely retain a microphone in an electrical connector.
It is necessary when constructing telephone hand pieces to include a microphone in the assembly. The microphone is typically mounted in a region of the telephone handpiece adjacent to where the user will talk. It is important that the microphone is securely retained and that it is not subjected to large amounts of shock, etc. This retention is typically achieved by positioning the microphone within a housing and securing the housing to an electrical connector within the telephone assembly. It is preferable that the housing have an acoustic insulating element therein, so as to provide an optimum transfer of the required speech to the electronic circuitry while obviating the effect of extraneous noise.
U.S. Pat. No. 4,984,268, assigned to ATandT Bell Laboratories, describes a microphone that is located in a gasket, forming an assembly that is inserted into a cavity in the handset, a cylindrical sponge having been positioned at the base of the cavity. U.S. Pat. No. 5,420,071, assigned to Motorola, describes an apparatus designed to isolate a microphone from the speaker audio unit of a telephone handset. The microphone is inserted into an insulator, where the insulator has circumferentially extending ridges encircling the insulator so as to prevent the removal of the insulator from a retaining cup. An extending tab is also provided which prevents the rotation of the insulator in the cup. The insulator/microphone combination is held within the retaining cup by means of an interference fit. A second US patent assigned to Motorola, U.S. Pat. No. 5,201,069 discloses a microphone that is sandwiched between two gaskets. This microphone/gasket sandwich is held together between the upper portion of the housing and its base, again the securing being achieved by means of an interference fit.
U.S. Pat. Nos. 5,410,608 and 5,615,273, both assigned to the UNEX Corporation, disclose the provision of a microphone within a boot and the retention of the microphone within the boot using a separate cover.
U.S. Pat. No. 5,823,820, assigned to the present assignees, discloses the provision of the microphone with a grommet. Again, the microphone is secured within its retainer by means of an interference fit.
One common feature of the aforementioned arrangements is the retention of the microphone by means of an interference fit. This arrangement is not very secure and it is possible that any vibration of the holder or housing, either as an unassembled component of a radio telephone or when actually in use may lead to the dislodgement of the microphone from its holder. There is, therefore, a need for a more secure means for retaining a microphone within its associated holder.
When mounted in radio or mobile telephones, it is preferable to mount the microphones in an I/O connector, so as to reduce the number of connectors used and the space taken up by individual connectors. Typically, the microphone is positioned within a housing in the connector and a cover is placed over the assembly, thereby retaining the microphone in position. The use of the cover has associated problems in that it adds to the overall thickness of the connector, a problem that is most acute when trying to minimize the overall size of the handset and components utilized.
Therefore a need exists for an alternative mounting arrangement for microphones within connectors of a radio telephone handset, an arrangement that effects the secure retention of the microphone within the mobile telephone with a minimal number of components.
These needs and others are addressed by the present invention which provides a mounting arrangement for connecting an electrical device within a wireless telephone. The mounting arrangement comprises a housing having an electrical device receiving portion and an enveloping portion adapted to envelop the electrical device. The enveloping portion has at least two outwardly projecting retention tabs, the tabs adapted to co-operate and engage with corresponding retention portions within the receiving portion. On insertion of the enveloped electrical device within the receiving portion, the retention tabs engage with the retention portions, thereby securing the enveloping portion and enveloped electrical device within the receiving portion.
The electrical device is preferably a microphone, which is held within an acoustically insulating enveloping portion or mounting boot.
The receiving portion preferably comprises a base and transversely projecting wall portions. The wall portions extend about a perimeter of the base, thereby defining a perimeter of the receiving portion.
Desirably a guide region is provided in the wall portions, such that the wall portions do not extend completely about the base. The guide portion is adapted to engage with a corresponding guide provided on the enveloping portion.
The retention portions are preferably formed in the wall portions of the receiving portion. The retention portions desirably have side walls, which are substantially parallel to the wall portions, and additionally an upper engagement surface, substantially parallel to the base of the receiving portion.
The receiving portion is preferably provided with connector terminals, the connector terminals adapted to be electrically engageable with corresponding terminals on the electrical device. The connector terminals are desirably positioned near to the base of the receiving portion, such that on insertion of the enveloped electrical device within the receiving portion, the connector terminals within the receiving portion and the terminals on the electrical device are in electrical engagement.
The enveloping portion preferably comprises a base region and upwardly extending side walls. An inner surface of the side walls defines an enveloping region adapted to receive and envelop an inserted microphone. At the base region, the inner surface further defines an entry port through which a microphone may be inserted into the enveloping region, and at an upper region of the enveloping portion the inner surface of the side walls further define an exit aperture. The exit aperture is dimensioned to enable an active surface of an inserted microphone to be exposed.
The projecting retention tabs preferably project from an outer surface of the side walls of the enveloping portion. The tabs have a taper region extending outwardly and upwardly from the base region of the enveloping portion, and an engaging portion extending from the outer surface of the side walls to an outermost point of the taper region The engaging portion is adapted, in use, to engage with the engagement surface of the retention portion.
The enveloping portion is preferably formed from a resilient material, preferably rubber.
Desirably the housing is integrally formed on an electrical connector, the electrical connector having mounting means adapted to effect the mounting of the connector within the telephone.
The invention additionally provides a mounting arrangement for connecting a microphone within a mobile telephone, the mounting arrangement comprising a housing having a microphone insertion cavity and a mounting boot adapted to accommodate the microphone. The boot has at least two projecting retention tabs adapted to co-operate and engage with corresponding retention portions within the cavity. On insertion of the boot and accommodated microphone within the insertion cavity, the retention tabs engage with the retention portions, thereby securing the boot and accommodated microphone within the cavity.
The projecting retention tabs preferably project from an outer wall of the boot, and comprise a taper region extending outwardly and upwardly from the base of the boot to a distal region, and an engaging portion, the engaging portion extending from the outer wall of the boot to the distal region. The engaging portion is adapted, in use, to engage with an upper surface of the retention portion.
The cavity preferably comprises a base and side wall with the retention portions being formed in the side walls of the cavity. The retention portions have side walls and an upper surface. The upper surface is adapted, in use, to engage with the engaging portion of the retention tabs.
The inner surface of the cavity side walls extend about the side of the cavity, defining a cavity area substantially equivalent to the outer perimeter of the enveloping portion.
The invention also provides a method for securing a microphone within an electrical connector. The method desirably comprises the steps of fitting the microphone within a mounting boot and then placing the enveloped microphone into a receiving portion of the electrical connector. The enveloped microphone is positioned into the receiving portion until terminals on the base of the microphone come into electrical engagement with connector terminals provided within the receiving portion. Tabs, radially extending from an outer wall of the mounting boot snap-fit into interengagement with retention portions provided on the side walls of the receiving portion, thereby securing the microphone within the electrical connector.